Mark Adam Cave, accused of beating his mother to death and hiding her body, struggled to stay composed Monday when he took the witness stand during his trial for murder.

He tearfully told jurors his life story — from his "fairly normal" early childhood to his troubled teenage years to an adult life defined by his unhealthy relationship with his abusive, mentally ill mother. Few details were spared.

Monday was the last day of testimony in Cave's trial on charges of murder, tampering with evidence and fraudulent use of a credit card. He is accused of killing Sharon Howard, 54, hiding her body in a Herbie trash container and cashing her Social Security benefits after her death. The trial in Fayette Circuit Court began May 6.

Howard's decomposed body was found on Trade Center Drive in Lexington on Feb. 1, 2012, about 7 months after she was killed. Prosecutors have said there is no question Cave is responsible for the "brutal" beating.

Cave's attorneys have said the killing followed a lifetime of torment by his drug-addicted mother, who was bipolar and depressed and showed signs of schizophrenia. She was diagnosed when Cave was 12.

Cave's four-hour testimony Monday came to a halt for minutes at a time while he sobbed, burying his bright-red face in a napkin and rocking back and forth in his chair.

He told jurors of the sudden death of his infant son in 2008 and the death of his father shortly after. Those losses led him to use drugs heavily, he said.

"I didn't care. I was at rock bottom," he said.

Prosecutors were not swayed by the display of emotion. Assistant Commonwealth's Attorney Lou Anna Red Corn questioned Cave at length about the seemingly methodical steps he took to cover up the killing — including concealing the Herbie in a wooded area — casting doubt on Cave's contention that he didn't mean to kill his mother and didn't remember doing it.

After years of estrangement, Cave and Howard began living together periodically in 2006. After his son died, she introduced him to crack cocaine, and they became dependent on each other — each would buy drugs for the other when they could afford it, Cave said.

They fought constantly, he said.

The night of the killing, Cave had taken a handful of his mother's anxiety medication in an attempt to kill himself after a particularly nasty argument in which Howard told him that he was an unfit father and that was why "God took your son away," he said.

He passed out for a few hours and woke up to the sound of Howard beating on his bedroom door, insulting him and yelling at him for stealing her meds, he said.

He told the jury he must have "snapped." He said he remembers the killing only in flashes and "nightmares."

But prosecutors noted that Cave hid the body; disposed of the weapon, which has not been found or identified; moved to Florida for several months; and lied to friends, family and police about Howard's whereabouts.

"Even if you say you can't remember what you did, everything that you did made sense under the circumstances, didn't it? To conceal, to hide, to run, to lie?" Red Corn asked.

Cave agreed but said his actions weren't what they seemed.

"To me, it looks like I freaked out," he said. "It wasn't something that was planned — wasn't something I wanted to happen."

After testimony from Cave's brother, Harold Lee Cave — who also told the jury of the brothers' abuse at the hands of Howard — the defense team rested its case.